As the final stage in our exploration of the structure and function of this molecule, let's visit PDBsum. Some information here will overlap with what you have seen already, but some aspects are easiest to see within this resource.
Scroll down on the main page for 1TPH. What is the reaction catalysed by this enzyme?
Now click on the Catalytic Site Atlas CSA link (found at the right hand side towards the bottom of the Links menu). The introduction section for this entry may help you to understand the function of this enzyme better.
Return to the main PDBsum entry and click on the protein tab. The schematic diagram shows the secondary structure of the protein, together with the amino acids involved in interacting with the ligand and those involved in the catalytic function. Amino acids surrounded by red boxes are known to be involved in the catalytic function and amino acids with red dots above are involved in interacting with the ligand. This is a more complete list than that obtained from the paper abstract. Use this to answer question 10.
Now click on the ligands tab and use the information to answer the questions.
Towards the bottom of this page you should see a schematic diagram showing the interactions between the protein and the ligand. The following link (also available via the LIGPLOT link) gives a key to the symbols used in the diagram. Use the diagram to identify 2 amino acids which are involved in hydrogen bonding to the ligand.
Finally click on the Prot-Prot tab at the top of the page to look briefly at the interactions between the two polypeptide chains in the dimer. Describe briefly the interactions between the two chains.